WASTE RETENTION DEVICE
The waste retention device with a deformable skirt and threaded rods effectively addresses the issue of small debris retention in stormwater systems, enhancing installation efficiency and reducing maintenance costs while preventing well deterioration.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- ECOSAFE
- Filing Date
- 2024-11-14
- Publication Date
- 2026-05-15
AI Technical Summary
Existing stormwater drainage systems fail to effectively retain small debris, leading to blockages and pollution, and current filtration solutions are costly, labor-intensive, and prone to deterioration due to anchoring and manufacturing inconsistencies.
A waste retention device with a hollow container and a deformable skirt having smaller mesh sizes than the well's opening, secured by threaded rods, allows easy installation and minimizes well damage, directing small debris into the container for easy removal.
The device efficiently retains small debris, reduces installation time and costs, and minimizes well deterioration by adapting to manufacturing tolerances without anchoring, ensuring continuous drainage and easy maintenance.
Smart Images
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Abstract
Description
Title of the invention: WASTE RETENTION DEVICE TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to the treatment of rainwater, and more particularly to the retention of waste carried by rainwater which is collected via collection wells.
[0002] Stormwater drainage systems are supplied by stormwater collection wells such as manholes located in the roadway, or catch basins located along gutters extending along sidewalks. These stormwater collection wells have a lateral peripheral wall defining an upper opening which is generally partially covered by a grate over which vehicles and people can drive or walk.
[0003] The grates of rainwater collection wells have relatively large mesh sizes designed to retain larger debris and prevent it from entering the underground section of the rainwater drainage system. However, these large mesh sizes cannot retain smaller debris (i.e., debris smaller than the mesh size). This debris then circulates in the underground section of the rainwater drainage system and can cause blockages or be carried to the sea, where it pollutes.
[0004] Among small waste items, some have a higher pollution potential. For example, it is considered that a single cigarette butt is enough to contaminate a volume of 500 litres of water.
[0005] To solve this problem, it has been proposed to add to the rainwater collection wells a filter in the form of a rigid and flat plate with smaller mesh than the mesh of the grid.
[0006] However, the installation of such a filter is achieved by anchoring retaining elements to the lateral peripheral wall of the well. This anchoring creates cracks in which vegetation can eventually develop, and these cracks can be further enlarged by frost. This leads to a problem of accelerated deterioration of the well.
[0007] Furthermore, rainwater collection wells have variable and imprecise dimensions of their top opening and depth, particularly due to manufacturing tolerances. On-site adaptation of the filter is therefore generally necessary, especially to prevent small debris from passing between the filter and the well's lateral perimeter wall. Standardizing a filter for multiple wells is thus complicated.
[0008] Finally, adapting the filter on site and anchoring the holding elements requires a significant amount of labor time, which makes the filter very expensive. Description of the invention
[0009] One problem proposed by the present invention is to provide a waste retention device which is easy and quick to install in a rainwater collection well in order to effectively limit the penetration of small waste into the underground part of a rainwater network.
[0010] Simultaneously, the invention aims to provide a waste retention device whose installation in a rainwater collection well presents little, if any, risk of deterioration of said well.
[0011] To reach these objects and others, the invention proposes a waste retention device, intended to be placed in a rainwater collection well with a lateral peripheral wall defining an upper opening, comprising: - a hollow container delimiting a cavity between a container bottom wall and a container side perimeter wall extending from the bottom wall to an upper perimeter edge defining an inlet opening of the container cavity, said container being made of a first material having a first rigidity, - a skirt with an openwork structure having a through-hole with a cross-section having dimensions less than or equal to the dimensions of the cross-section of the container inlet opening, said skirt being shaped and dimensioned to extend radially from and away from the container side perimeter wall along the entire periphery of the container inlet opening when said through-hole is positioned opposite said container inlet opening, - means of support, shaped so as to bear against the lateral peripheral wall of the well by protruding from the lateral peripheral wall of the container, and in which the skirt is made of a second material having a second stiffness lower than the first stiffness.
[0012] The holding means allow the container to be placed quickly and easily in the well, leaving a peripheral space between the container's lateral peripheral wall and the well's lateral peripheral wall. The container is preferably positioned substantially concentrically with the well's inlet.
[0013] Securing the container in the well by simply pressing it against the lateral peripheral wall of the well prevents damage to the well and compensates for manufacturing tolerances.
[0014] The openwork structure of the skirt has mesh sizes smaller than those of the well screen, and deemed sufficient to retain small debris. The mesh size of the skirt will therefore be chosen according to the smallest debris to be retained.
[0015] In practice, the skirt has a periphery whose dimensions are greater than or equal to the dimensions of the upper opening of the well. Due to its lower rigidity than that of the container, the skirt can be adapted by deformation so as to bear against the lateral peripheral wall of the well, precisely filling the peripheral space between the lateral peripheral wall of the container and the lateral peripheral wall of the well, with a funnel shape whose cross-section decreases downwards towards the upper opening of the well.
[0016] When rainwater containing small debris enters the well, it flows directly to the bottom of the well through the peripheral space between the container's side wall and the well's side wall (generally, it runs down the well's side wall). The small debris is retained by the perforated structure of the skirt, which, thanks to its funnel shape, directs the debris into the container where it accumulates, thus freeing the skirt for water flow. Periodically, a maintenance worker can remove the debris from the container, for example, using a vacuum cleaner.
[0017] In one particular embodiment of the present invention, the skirt may be attached to the container. In another particular embodiment of the present invention, the skirt may be separate from the container.
[0018] Preferably, the holding means may comprise a plurality of threaded rods, each cooperating by means of a threaded helical connection with the peripheral lateral wall of the container. The holding means are thus simple in structure and are also very easy and quick to use.
[0019] Advantageously, the helical threaded connection between the threaded rod and the peripheral side wall of the container can be provided by a nut attached to and fixed to the peripheral side wall of the container. The container can thus have relatively thin walls, making it easy and inexpensive to manufacture. The nuts can preferably be rivet nuts that are attached and secured by crimping into respective holes provided in the peripheral side wall of the container.
[0020] Alternatively, if the walls have sufficient thickness, the helical threaded connection between the threaded rod and the peripheral lateral wall of the container can be provided by internal tapping of holes made in the peripheral lateral wall of the container.
[0021] Preferably, the skirt with an openwork structure can be formed by a mesh, preferably made of plastic. Good results have been obtained with a mesh made of high-density polyethylene (HDPE).
[0022] Advantageously, the cross-sectional through-hole can have dimensions smaller than the dimensions of the container inlet. This allows for more reliable guidance of the waste into the container cavity.
[0023] This also limits the risk that the skirt, deforming under the weight of waste, could become so distorted that the light through it is no longer aligned with the container's inlet opening. This is particularly useful when the skirt is not attached to the container.
[0024] Preferably, for better durability over time, the first material can be a metal, even more preferably a stainless steel.
[0025] Advantageously, the container can be manufactured by cutting from a flat blank of first material, shaped by folding, and preferably held in shape by a weld-free fastening.
[0026] The folding allows for quick, easy and inexpensive manufacturing, without damage to the flat blank of the primary material (which can, for example, be a painted or lacquered sheet).
[0027] The absence of welding limits the risk of heat-affected zones (HAZs) which are often prone to accelerated deterioration, for example by corrosion. A weld-free fastening can, for example, be achieved using rivets.
[0028] Brackets may be provided to fix the relative position of the different sections of the container's side perimeter wall. Alternatively, partial overlaps of sections of the container's side perimeter wall may be used.
[0029] Preferably, the skirt may include one or more slits extending radially from its periphery in the direction of the light passing through and stopping before the light passing through.
[0030] The slit or slits allow parts of the skirt to overlap each other to facilitate the shaping of the skirt into a funnel shape.
[0031] Advantageously, it can be foreseen that: - the container has, in a plane generally parallel to the inlet opening, a rectangular or square cross-section, - the skirt has an external rectangular or square shape with four corners, and includes at least one slit extending from one of its corners and along one of its diagonals.
[0032] A rectangular container and a rectangular skirt will be preferred for wells with a lateral peripheral wall defining a rectangular top opening.
[0033] A square container and a square skirt will be preferred for wells with a lateral peripheral wall defining a square or circular top opening.
[0034] Preferably, the bottom wall of the container and / or the peripheral side wall of the container can be perforated.
[0035] The mesh of the container's bottom wall and / or the container's peripheral side wall is then at least as small as that of the perforated structure of the skirt, and also allow rainwater to pass through the container. This can be useful in cases where the rainwater flow is such that it does not simply run down the side perimeter wall of the well but is projected towards the center of the well beyond the peripheral space between the side perimeter wall of the container and the side perimeter wall of the well.
[0036] According to another aspect, the present invention proposes the use of a waste retention device as previously described and with a skirt separate from the container, in which: - The waste retention device is inserted into a rainwater collection well with a lateral peripheral wall, orienting the cavity's inlet opening upwards. - The holding means are used to bring them into contact with the lateral peripheral wall of the well, so as to create a peripheral space between the lateral peripheral wall of the container and the lateral peripheral wall of the well, - the skirt is positioned in contact: a. on the upper peripheral edge of the container by placing said through-hole in correspondence with said container inlet, and b. on the lateral peripheral wall of the well, so as to fill the peripheral space between the peripheral side wall of the container and the peripheral side wall of the well, while shaping the skirt into a funnel shape with a cross-section decreasing downwards away from the upper opening of the well.
[0037] According to another aspect, the present invention proposes the use of a waste retention device as previously described and with a skirt attached to the container, in which: - The waste retention device is inserted into a rainwater collection well with a lateral peripheral wall, orienting the cavity's inlet opening upwards. - the holding means are used to bring them into contact with the peripheral lateral wall of the well, so as to create a peripheral space between the peripheral lateral wall of the container and the peripheral lateral wall of the well, - the skirt is placed in contact with the peripheral lateral wall of the well, so as to fill the peripheral space between the peripheral lateral wall of the container and the peripheral lateral wall of the well, while shaping the skirt into a funnel shape with a cross-section decreasing downwards away from the upper opening of the well. SUMMARY DESCRIPTION OF THE DRAWINGS
[0038] Other objects, features and advantages of the present invention will become apparent from the following description of particular embodiments, made in relation to the accompanying figures, among which:
[0039] [Fig-1] Fig. 1 is a schematic top view of a container usable in a first particular embodiment of a waste retention device according to the present invention;
[0040] [Fig.2] The [Fig.2] is a schematic top view of a skirt usable with the container of the [Fig.1];
[0041] [Fig.3] The [Fig.3] is a schematic top view of a waste retention device according to a first particular embodiment of the present invention, comprising a container illustrated in the [Fig.1] and a skirt illustrated in the [Fig.2];
[0042] [Fig.4] The [Fig.4] is a schematic side view of the waste retention device of the [Fig.3];
[0043] [Fig.5] The [Fig.5] is a schematic partial cross-sectional view illustrating a first step in the installation of the waste retention device of the [Fig.3] in a stormwater collection manhole type well;
[0044] [Fig.6] The [Fig.6] is a schematic cross-sectional view illustrating a second step in the installation of the waste retention device of the [Fig.3] in a stormwater collection manhole type well;
[0045] [Fig.7] The [Fig.7] is a schematic cross-sectional view illustrating a third step in the installation of the waste retention device of the [Fig.3] in a stormwater collection manhole type well;
[0046] [Fig.8] The [Fig.8] is a schematic cross-sectional view illustrating a fourth step in the installation of the waste retention device of the [Fig.3] in a stormwater collection manhole type well;
[0047] [Fig.9] The [Fig.9] is a schematic top view of a container usable in a second particular embodiment of a waste retention device according to the present invention;
[0048] [Fig. 10] [Fig. 10] is a schematic top view of a waste retention device according to a second particular embodiment of the present invention, comprising a container illustrated in [Fig. 9] and a skirt; and
[0049] [Fig. 11] The [Fig. 11] is a schematic cross-sectional view showing the waste retention device of the [Fig. 10] installed in a storm drain type well for rainwater collection. DESCRIPTION OF PREFERRED IMPLEMENTATION METHODS
[0050] When identical numerical references are used in several figures, embodiments or variants of the invention, these numerical references designate identical or similar elements in each of the figures, embodiments or variants.
[0051] Figures 1 to 4 illustrate a first embodiment of a waste retention device 1 according to the present invention.
[0052] This waste retention device 1 is intended to be placed in a rainwater collection well 2 with a lateral peripheral wall 3 defining a top opening 4 (Figures 5 to 8). The grid 5 of the well 2 has mesh 6 that is (too) large to retain small waste such as cigarette butts.
[0053] The waste retention device 1 comprises a hollow container 7 ([Fig.l]) delimiting a cavity 8 between a bottom wall 9 of container 7 and a lateral peripheral wall 10 of container 7 extending from the bottom wall 9 to an upper peripheral edge 11 defining an inlet orifice 12 of the cavity 8 of container 7.
[0054] Here, the inlet orifice 12 extends substantially along a plane PL. A planar shape is not, however, essential, and an oblique or other orientation is also possible.
[0055] Said container 7 is made of a first material having a first rigidity. The first material is a metal, preferably a stainless steel.
[0056] As can be seen more particularly in [Fig.1], the waste retention device 1 further includes holding means 15, shaped to come to rest against the peripheral lateral wall 3 of the well 2 by protruding on the peripheral lateral wall 10 of the container 7.
[0057] The holding means 15 comprise a plurality of threaded rods 16a to 16d each cooperating by means of a threaded helical link 17a to 17d with the lateral peripheral wall 10 of container 7.
[0058] The helical threaded connections 17a to 17d between the threaded rods 16a to 16d (which are specifically wing nuts here) and the peripheral side wall 10 of container 7 are provided here by nuts 170a to 170d attached and fixed (preferably by crimping) to the peripheral side wall 10 of container 7.
[0059] The threaded rods 16a to 16d may belong to screws of a type other than wing head screws. For example, screws with a head fitted with a ring or, more generally, with any operating mechanism facilitating manual operation may be used.
[0060] The container 7 is here manufactured by cutting from a flat blank of primary material, shaped by folding and held in shape by a weld-free fastening.
[0061] In this case, the container 7 is held in shape by means of rivets 19. The rivets 19 fix the relative position of different sections forming the lateral peripheral wall 10 of the container 7, which partially overlap each other. One could as an alternative, have no overlap between the different sections forming the peripheral side wall 10 of container 7, and use brackets also added and fixed by rivets 19.
[0062] The waste retention device 1 also includes a skirt 13 ([Fig.2]) with an openwork structure having a through light 14 with a cross-section having dimensions (L14 and L14') less than or equal to the dimensions (L12 and L12') of the cross-section of the inlet orifice 12 of container 7, said skirt 13 being shaped and dimensioned to extend radially from and away from the peripheral side wall 10 of container 7 along the entire periphery of the inlet orifice 12 of container 7 when said through light 14 is placed in correspondence with said inlet orifice 12 of container 7 (as is more clearly seen in [Fig.3]).
[0063] The skirt 13 is made of a second material having a second stiffness lower than the first stiffness.
[0064] The skirt with an openwork structure can advantageously be formed by a mesh, preferably made of plastic such as high-density polyethylene (HDPE).
[0065] The openwork structure of the skirt 13 has meshes 18 with dimensions smaller than those of the well screen, and deemed sufficient to retain small debris. The mesh size of the skirt will therefore be chosen according to the smallest debris to be retained. In practice, good results have been obtained with meshes 18 having a square cross-section of 6 mm per side.
[0066] In practice, the skirt 13 has a periphery whose external dimensions L13 and L13' ([Fig.2]) are greater than or equal to the dimensions L4 and L4' of the upper orifice 4 of the well 2 (figures 5 to 8, L4' is not visible on figures 5 to 8 because it is perpendicular to the cutting plane).
[0067] As is particularly visible in [Fig.3], the light through 14 has a cross-section having dimensions L14 and L14' smaller than the dimensions L12 and L12' of the inlet orifice 12 of container 7.
[0068] As better illustrated in Figures 2 and 3, the skirt 13 has four slots 20a to 20d extending radially from the periphery of the skirt 13 towards the through-hole 14 and stopping before the through-hole 14. Slot 20a allows the sides 201a and 202a of the skirt 13 to overlap each other to facilitate shaping the skirt 13 into a funnel shape. The same applies to the sides 201b and 202b defined by slot 20b, to the sides 201c and 202c defined by slot 20c, and to the sides 201d and 202d defined by slot 20d.
[0069] It can be seen more particularly in Figures 1 and 4 that the bottom wall 9 of container 7 and the side peripheral wall 10 of container 7 are perforated. The perforated nature of the bottom wall 9 and the side peripheral wall 10 is obtained here by circular through lights 21. In practice good results have been obtained with circular through lights 21 of 6 mm diameter, the container 7 having been made from a flat blank of R6 T9 sheet metal.
[0070] In the embodiment of waste retention device 1 illustrated in Figures 1 to 4: - the container 7 presents, in a plane generally parallel to the inlet orifice 12 (in the PI plane here), a square cross-section ([Fig.l]), - the skirt 13 has a square external shape with four corners, and has four slits 20a to 20d extending respectively from a corner and along one of the diagonals of the square skirt 13.
[0071] Such a waste retention device 1 is particularly suitable for use in a well 2 of the type rainwater collection manhole with a lateral peripheral wall 3 defining a top opening 4 with a square or circular cross-section.
[0072] In the variant illustrated in figures 1 to 4, the skirt 13 is separable from the container 7.
[0073] However, a skirt 13 attached to the container 7 may be used as an option. securing the skirt 13 to the upper peripheral edge 11 can be done by means of staples (preferably made of plastic) or by means of flexible plastic cable ties (for example marketed by the Swedish company Norma Sweden AB under the brand SERFLEX®).
[0074] The implementation of the waste retention device 1 of figures 1 to 4 will now be explained in relation to figures 5 to 8.
[0075] In a first step illustrated in [Fig.5], an operator introduces (according to the movement illustrated by arrow 22) the waste retention device 1 into a rainwater collection well 2 (here of the inspection chamber type) with a lateral peripheral wall 3, orienting the inlet orifice 12 of the cavity 8 upwards.
[0076] The plane PI in which the inlet orifice 12 extends coincides here with a substantially horizontal plane P.
[0077] The operator then applies the wing head screws 16a to 16d of the holding means 15 to bring them into contact with the peripheral lateral wall 3 of the well 2, leaving a peripheral space ESP between the peripheral lateral wall 10 of container 7 and the peripheral lateral wall 3 of the well 2.
[0078] The container 7 is thus reliably and quickly immobilized at height in the well 2, and is preferably substantially centered in the middle of the lateral peripheral wall 3 of the well 2. No additional accessories are required for holding the waste retention device 1 in the well 2.
[0079] The peripheral lateral wall 3 of the well 2 is not altered by contact with the free ends of the wing nuts 16a to 16d (which may also, if what is needed is to be equipped with a pad made of resilient material such as rubber or an elastomer).
[0080] In a subsequent step illustrated in [Fig.6], the operator introduces the skirt 13 into the well 2 according to the movement illustrated by the arrow 23.
[0081] Because the external dimensions L13 and L13' of the skirt 13 are larger than the dimensions L4 and L4' of the upper opening 4 defined by the lateral peripheral wall 3 of the well 2, the skirt 13 deforms (due to its lower rigidity) as illustrated in [Fig. 7]: the periphery of the skirt 13 rests against the lateral peripheral wall 3 of the well 2, and the skirt 13 takes on a shape essentially resembling a funnel with a cross-section decreasing downwards towards the upper opening 4 of the well 2. A funnel shape is understood to mean a shape essentially frustoconical. The slots 20a to 20d facilitate this shaping by allowing the faces 201a and 202a, 201b and 202b, 201c and 202c, and finally 201d and 202d to overlap.
[0082] The operator then continues the downward movement of the skirt 13 in the well 2 illustrated by the arrow 23, until reaching the position illustrated in [Fig.8] in which the skirt is positioned in support: a. on the upper peripheral edge 11 of the container 7 with said through-hole 14 placed in correspondence with said inlet orifice 12 of container 7, and b. on the lateral peripheral wall 3 of well 2.
[0083] Thus arranged, the skirt 13 fills the peripheral space ESP provided between the peripheral side wall 10 of container 7 and the peripheral side wall 3 of well 2, and has a funnel shape with a cross-section decreasing downwards away from the upper orifice 4 of well 2.
[0084] Continuous contact is formed between the skirt 13 and the peripheral lateral wall 3 of the well 2 so that no waste entering the well 2 can escape from the waste retention device 1.
[0085] Finally, the operator puts the well grid 5 back in place.
[0086] When rainwater containing small debris enters well 2 through the mesh 6 of the grid 5, it flows directly to the bottom of well 2 through the peripheral space ESP formed between the lateral peripheral wall 10 of container 7 and the lateral peripheral wall 3 of well 2 (generally, it runs down the lateral peripheral wall 3 of well 2). Small debris (whose dimensions prevent passage through the mesh 18 of the skirt 13), and particularly cigarette butts, are retained by the perforated structure of the skirt 13, which, thanks to its funnel shape, directs the debris into the cavity 8 of container 7 where it accumulates. Periodically, a The road maintenance worker can come and remove the waste from container 7, for example using a vacuum cleaner.
[0087] The skirt having a funnel shape, it is inclined vertically above the peripheral space ESP provided between the peripheral side wall 10 of container 7 and the peripheral side wall 3 of well 2: there is therefore little risk that waste could accumulate in such a way as to obstruct all the meshes 18 of the skirt 13. There is therefore little risk that the waste retention device 1 will be completely obstructed and prevent rainwater from being collected at the bottom of well 2.
[0088] In the variant in which the skirt 13 is integral with the container 7, the placement in a well 2 is carried out as follows: - the waste retention device 1 is introduced into the rainwater collection well 2 with a lateral peripheral wall 3, orienting the inlet orifice 12 of the cavity 8 upwards, - the holding means 15 are used to bring them into contact with the lateral peripheral wall 3 of the well 2, so as to create a peripheral space ESP between the lateral peripheral wall 10 of container 7 and the lateral peripheral wall 3 of the well 2, - the skirt 13 is placed in support on the peripheral lateral wall 3 of the well 2 (it even tends to come there on its own), so as to fill the peripheral space ESP provided between the peripheral lateral wall 10 of container 7 and the peripheral lateral wall 3 of the well 2, while shaping the skirt 13 into a funnel shape with a cross-section decreasing downwards away from the upper orifice 4 of the well 2.
[0089] Figures 9 and 10 illustrate a second embodiment of the waste retention device 1 according to the present invention. This differs from the waste retention device 1 of Figures 1 to 4 in that: - the container 7 presents, in a plane generally parallel to the inlet orifice 12 (in the PI plane here), a rectangular cross-section ([Fig.9]), - the skirt 13 has an external rectangular shape with four corners, and has four slits 20a to 20d extending respectively from a corner and along one of the diagonals of the rectangular skirt 13 ([Fig. 10]).
[0090] The threaded rods 16a to 16d are arranged only on two opposite sections of the lateral peripheral wall 10 of the container 7 (here the sections forming the long sides of the rectangular cross-section of the container 7).
[0091] The threaded rods 16a and 16b are arranged on a first section of the lateral peripheral wall 10, offset from the threaded rods 16c and 16d, which are arranged on a second section of the lateral peripheral wall 10, so that the threaded rods 16a to 16d can be easily handled by the operator and can present sufficient lengths without coming into conflict with each other in cavity 8 of container 7.
[0092] The second embodiment of waste retention device 1 is more suitable for being received in a drain-type well 2 arranged along gutters extending along the sidewalks, as illustrated in [Fig. 1 1].
[0093] The arrangements and operation of the second embodiment of waste retention device 1 are comparable to those of the first embodiment of waste retention device 1 which have been previously described, and will therefore not be explained in further detail.
[0094] The present invention is not limited to the embodiments that have been explicitly described, but includes the various variants and generalizations contained within the scope of the following claims.
Claims
Demands
1. Waste retention device (1), intended to be placed in a rainwater collection well (2) with a lateral peripheral wall (3) defining a top opening (4), comprising: - a hollow container (7) delimiting a cavity (8) between a bottom wall (9) of container (7) and a lateral peripheral wall (10) of container (7) extending from the bottom wall (9) to an upper peripheral edge (11) defining an inlet opening (12) of the cavity (8) of container (7), said container (7) being made of a first material having a first rigidity, - a skirt (13) with an openwork structure having a through light (14) with a cross-section having dimensions (L14, L14') less than or equal to the dimensions (L12, L12') of the cross-section of the inlet opening (12) of container (7),said skirt (13) being shaped and dimensioned to extend radially from and away from the peripheral lateral wall (10) of container (7) along the entire periphery of the inlet opening (12) of container (7) when said through-hole (14) is positioned in correspondence with said inlet opening (12) of container (7), - retaining means (15) shaped to bear against the peripheral lateral wall (3) of the well (2) by projecting onto the peripheral lateral wall (10) of container (7), and wherein the skirt (13) is made of a second material having a second stiffness lower than the first stiffness.
2. Waste retention device (1) according to claim 1, characterized in that the holding means (15) comprise a plurality of threaded rods (16a-16d) each cooperating by means of a threaded helical link (17a-17d) with the peripheral lateral wall (10) of container (7).
3. Waste retention device (1) according to claim 2, characterized in that the helical threaded connection (17a-17d) between the threaded rod (16a-16d) and the peripheral side wall (10) of container (7) is provided by a nut (170a-170d) attached and fixed to the peripheral side wall (10) of container (7).
4. Waste retention device (1) according to any one of claims 1 to 3, characterized in that the skirt (13) has a structure The openwork is formed by a wire mesh, preferably made of plastic.
5. Waste retention device (1) according to any one of claims 1 to 4, characterized in that the through light (14) has a cross section which has dimensions (L14, L14') smaller than the dimensions (L12, L12') of the inlet orifice (12) of container (7).
6. Waste retention device (1) according to any one of claims 1 to 5, characterized in that the first material is a metal, preferably a stainless steel.
7. Waste retention device (1) according to any one of claims 1 to 6, characterized in that the container (7) is manufactured by cutting from a flat blank of first material, shaped by folding, and preferably held in shape by a weld-free fastening.
8. Waste retention device (1) according to any one of claims 1 to 7, characterized in that the skirt (13) has one or more slots (20a-20d) extending radially from its periphery in the direction of the through light (14) and stopping before the through light (14).
9. Waste retention device (1) according to claim 8, characterized in that: - the container (7) has, in a plane (PI) generally parallel to the inlet opening (12), a rectangular or square cross-section, - the skirt (13) has an external rectangular or square shape with four corners, and includes at least one slot (20a-20d) extending from one of its corners and along one of its diagonals.
10. Waste retention device (1) according to any one of claims 1 to 9, characterized in that the bottom wall (9) of container (7) and / or the peripheral side wall (10) of container (7) is perforated.
11. Waste retention device (1) according to any one of claims 1 to 10, characterized in that the skirt (13) is integral with the container (7).
12. Use of a waste retention device (1) according to any one of claims 1 to 10, wherein: - the waste retention device (1) is introduced into a rainwater collection well (2) with a lateral peripheral wall (3), orienting the inlet orifice (12) of the cavity (8) upwards, - the holding means (15) are applied to bring them into contact with the lateral peripheral wall (3) of the well (2), so as to provide a peripheral space (ESP) between the lateral peripheral wall (10) of the container (7) and the lateral peripheral wall (3) of the well (2), - the skirt (13) is placed in contact: a. on the upper peripheral edge (11) of the container (7) by placing said through-hole (14) in correspondence with said inlet orifice (12) of the container (7), and b.on the peripheral side wall (3) of the well (2), so as to fill the peripheral space (ESP) between the peripheral side wall (10) of container (7) and the peripheral side wall (3) of the well (2), while shaping the skirt (13) into a funnel shape with a cross-section decreasing downwards away from the upper opening (4) of the well (2).
13. Use of a waste retention device (1) according to claim 11, wherein: - the waste retention device (1) is introduced into a rainwater collection well (2) with a lateral peripheral wall (3), orienting the inlet orifice (12) of the cavity (8) upwards, - the holding means (15) are stressed to bring them into contact with the lateral peripheral wall (3) of the well (2), so as to create a peripheral space (ESP) between the lateral peripheral wall (10) of the container (7) and the lateral peripheral wall (3) of the well (2), - the skirt (13) is positioned to rest against the lateral peripheral wall (3) of the well (2), so as to fill the peripheral space (ESP) between the lateral peripheral wall (10) of the container (7) and the lateral peripheral wall (3) of the well (2),while shaping the skirt (13) into a funnel shape with a cross-section decreasing downwards away from the upper opening (4) of the well (2).